October to March is the best time to visit. The weather is dry and cool — comfortable for walking and travelling between villages. December and January can be cold at night in the hills, so bring a layer. The light is clear and the forested landscape is at its most pleasant.
April to September brings the monsoon, which in Manipur is heavy and prolonged. Rain can make roads to outlying villages impassable and travel between towns unpredictable. The landscape is intensely green but the practical difficulties are real. If you are visiting in the wet season, allow extra time and check road conditions locally before attempting to reach villages outside town.
Inner Line Permits are required for all foreign visitors to Manipur and must be arranged before entering the state — ideally well in advance of arrival. Permits can be obtained at the Manipur Resident Commissioner offices in Delhi, Kolkata, Guwahati, and Silchar, or on arrival at Imphal airport and the Moreh border crossing. Arrange yours before you travel rather than relying on last-minute processing.